Icom IC-7100 PTT Issues

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When I bought a Digirig, my plan was to use it with my Icom IC-7100 and Direwolf for APRS activities. I also bought the MiniDin6 Audio cable to use with the 7100’s DATA1 jack.

However I was not able to get the 7100 to recognize PTT from the Digirig. Using the troubleshooting information on the Digirig website, I was able to determine the Digirig was in fact activating PTT thru its audio jack as expected. But the radio wasn’t going into transmit.

I soon learned the uart in the IC-7100 receives RTS as a result of an external PTT thru the Data1 jack (MiniDin6) but isn’t designed to do anything with it.

The past couple of years I had been using a Signalink with my 7100 for APRS. In that case I had the Signalink connected to the 7100’s control head with a RJ45 cable, so I knew the 7100 recognized PTT thru the control head. At the time I did have to build a special RJ45 cable. I also had to build a separate speaker cable since the 7100 doesn’t provide the speaker thru the RJ45 jack.

With that in mind I rechecked the Digirig store to see if such an IC-7100 cable was available for the Digirig. I did find the " ICOM RJ-45 Cable for Digirig Mobile", but it didn’t list the IC-7100.

So I went to work and built one to match my IC-7100 based on its schematics. As it turned out, I believe the Digirig one would have worked just fine for the 7100. Someone might want to confirm that before adding the IC-7100 to the list.

Anyway, at this point I’m successfully using my Digirig with my IC-7100 with Direwolf for APRS, JTDX, VarAC, JS8CALL, Fldigi. Just to be clear, I’m not using the MiniDin6 cable or Data1 port at all.

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Thanks for the info. The recommended cable kit for IC-7100 is the one with 13 pin accessory connector:

Looking at the manual for IC-7100 it states PTT support in MiniDin6:

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This may be limited to FM or UHF/VHF since the manual mentions “packet”. Try simulating the PTT by shorting the sleeve to ring 2 on the other end of the MiniDin6 cable with the radio on different bands to see if this is the case.

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I just tried shorting PTT to GND on the MiniDin6 cable, and your suspicion is correct. It only activates PTT in VHF/UHF. You said the recommended cable is the the one for the 13 pin ACC jack, but do you know if it also only works on VHF/UHF?

Apparently PTT in the control head must bypass the 13-pin ACC and 6-pin DATA jacks? I have the 7100’s service manual & schematics, but block diagrams don’t help explain firmware details like this.

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13 pin connector has multiple PTT lines for different bands. Digirig cable activates them all.
You can confirm the functions by shorting the PTT lines on the connector directly.

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Very good - I’m going to order one. I could build it, but I like your cables with the built-in ferrite beads. My RJ45 setup works, but it’s kind of clunky looking.

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